Finding the Fourth Proportional to 12,813.78, 19,219.98 and 3,929.10

Step by Step Solution

1. Step 1: Write the proportion equation
   12,813.78 : 19,219.98 = 3,929.10 : x
2. Step 2: Convert to fraction form
   12,813.78/19,219.98 = 3,929.10/x
3. Step 3: Cross multiply
   12,813.78x = 19,219.98 × 3,929.10
4. Step 4: Simplify right side
   12,813.78x = 75,517,223.42
5. Step 5: Solve for x
   x = 75,517,223.42/12,813.78
6. Step 6: Final answer
   x = 5,893.44